Semiconductor device having clips for connecting to external elements

ABSTRACT

A semiconductor device that has a semiconductor die having at least two opposing major electrodes and a control electrode. Conductive clips, each having a base portion and a contact portion, are connected to respective electrodes at their bases by a respective layer of conductive material. A passivation layer is disposed on at least one of the electrodes and surrounds the layers of conductive material. The base portion and the contact portion of one of the clips are connected by an extension, which extends between the major surfaces of the semiconductor die.

RELATED APPLICATIONS

This application is related to U.S. application Ser. No. 09/819,774,filed Mar. 28, 2001, by Martin Standing and Hazel D. Schofield entitledChip Scale Surface Mounted Device and Process of Manufacture.

BACKGROUND OF THE INVENTION

The present invention relates to semiconductor devices and moreparticularly to surface-mounted semiconductor devices having clips forconnecting to external elements.

To be used in electronic circuits, semiconductor dies are packaged toform semiconductor devices which may be directly connectable to externalelements such as conductive pads on a substrate. The packaging ofelectronic devices provides several functions. Protection of thesemiconductor die against moisture and other damaging environmentalelements, electrical connection to external elements and thermalmanagement of the heat generated by the semiconductor die are among themost important functions of an electronic package. Conventionally knownpackages such as DIP and SOIC packages address these functions. Thesepackages often use a lead frame structure which in some cases are 4-5time the size of the semiconductor die. Thus, packaging of asemiconductor die according to conventional designs often results in asemiconductor device which is much larger than the die itself.

The trend toward miniaturization of electronic systems compels themaximum utilization of space. One way to maximize space utilization isto minimize the size of components in the device to thereby increase thecomponent density. While increasing component density leads tomaximization of space utility, other challenges such as efficient heatreduction and reduction of parasitic electrical effects due for exampleto connection resistivity must also be addressed in any design.

SUMMARY OF THE INVENTION

A semiconductor device according to the present invention includes asemiconductor die having at least two opposing major electrodes disposedon its major surfaces. Each electrode has connected thereto a conductiveclip. Each clip includes a contact portion for making electrical contactwith an external element, such as conductive pads on a substrate, and abase portion connected to an electrode. The contact portions of theclips are disposed on one side of the semiconductor die. To effect thisarrangement at least one of the clips is provided with an extension thatconnects its base portion to its contact portion and extends between themajor surfaces of the die. This clip provides the shortest possible pathbetween the backside electrode of a die to the external element therebyreducing parasitic resistance and inductance in the package caused bythe connection itself.

To reduce the footprint of a semiconductor device according to thepresent invention contact portions of the clips may be oriented to bedisposed directly under the semiconductor die when the device isconnected to conductive pads of a substrate.

Alternatively, the contact portion of the clip having the extension maybe directed away from the area under the die in order to provide moreroom for the conductive pads on the substrate that are disposed underthe die.

Clips of varying shapes may be used in a semiconductor device accordingto the present invention. For example, in a first embodiment, each clipmay include a base portion and a contact portion connected and spaced byan extension. In other embodiments, some of the clips may include a flatbase portion and contact portions disposed directly on the flat baseportion. The contact portions in the latter clips may be semispherical,cylindrical or raised portions extending from the flat base portion.

Other features and advantages of the present invention will becomeapparent from the following description of the invention which refers tothe accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A shows a side view of a semiconductor device according to thefirst embodiment of the invention.

FIG. 1B shows a bottom plan view of the device shown in FIG. 1A.

FIG. 2A shows a side view of a clip used in the device shown in FIG. 1A.

FIG. 2B is a view of the clip shown in FIG. 2A viewed in the directionof 2B—2B arrows.

FIG. 3A shows a side view of a clip used in the device shown in FIG. 1A.

FIG. 3B is a view of the clip shown in FIG. 3A viewed in the directionof 3B—3B arrows.

FIG. 3C is a view of the clip shown in FIG. 3A viewed in the directionof 3C—3C arrows.

FIG. 4 shows a semiconductor wafer having a plurality of semiconductordies formed therein according to prior art.

FIG. 5 shows the wafer shown in FIG. 4 having a passivation layer formedthereon with openings that expose portions of the top electrodes of thesemiconductor die.

FIG. 6 shows the wafer shown in FIG. 5 with clips attached to the topelectrodes of the semiconductor dies.

FIG. 7A shows a bottom view of a semiconductor device according to thesecond embodiment of the present invention.

FIG. 7B shows a side view of the device shown in FIG. 7 viewed in thedirection of 8—8 arrows.

FIGS. 8A and 8B show respectively a top plan view and a side view(looking in the direction of arrows 8B—8B in FIG. 8A) of a clip used inthe second embodiment of the invention.

FIGS. 8C and 8D show respectively a top plan view and a side view(looking in the direction of arrows 8D—8D in FIG. 8C) of a clip used inthe second embodiment of the invention.

FIG. 9 shows a cross-sectional view of the device shown in FIG. 7looking in the direction of line 9—9.

FIGS. 10A—10B show respectively top and side views of the clips used inthe second embodiment of the present invention.

FIGS. 11A—11B show respectively top and side views of another example ofclips which may be used in the second embodiment of the presentinvention.

FIGS. 12A—12B show respectively top and side views of another example ofclips which may be used in the second embodiment of the presentinvention.

FIG. 13 shows the semiconductor device of the first embodiment mountedon a substrate.

FIG. 14 shows the semiconductor device of the second embodiment mountedon a substrate.

DETAILED DESCRIPTION OF THE DRAWINGS

Referring to FIGS. 1A and 1B, the first embodiment of a semiconductordevice according to the present invention includes semiconductor die 10.Semiconductor die 10 according to a preferred embodiment may be a powerMOSFET. The present invention, however, is not limited to power MOSFETs.Other electronic semiconductor die such as IGBTs, power diodes, and thelike may also be used instead of a MOSFET.

Semiconductor die 10 includes two opposing major surfaces. Disposed onits first major surface, semiconductor 10 has first major electrode 12and on its second major surface, second major electrode 14.Semiconductor die 10 also includes control electrode 16 which isdisposed on the first major surface of the semiconductor die 10, and isinsulated from first major electrode 12. In a MOSFET, which is used inthe preferred embodiment, first and second major electrodes may besource and drain contacts respectively while control electrode 16 isconventionally referred to as the gate electrode.

Control electrode 16 receives control signals from an externalcontroller, which signals switch the current that flows between firstmajor electrode 12 and second major electrode 14 when semiconductordevice 8 of the present invention is incorporated in its place within anelectronic circuit.

Semiconductor device 8 according to the first embodiment includes aplurality of clips 18, 20, 22. Each clip includes a base portion 24, 26,28 and a contact portion 30, 32, 34. The function of contact portions30, 32, 34 is to make electrical contact with external elements. Baseportions 24, 26, 28 are electrically connected to second major electrode14, first major electrode 26 and control electrode 16 respectively by alayer of die attach material 36, such as solder or a conductive epoxysuch as a silver loaded epoxy. Passivation layer 38 covers first majorelectrode 12 and control electrode 16 except for portions that haveconductive attach material 36 disposed thereon for making electricalconnection with base portions 26, 28 of respective clips 20, 22.

Each clip 18, 20, 22, also includes an extension 19, 21, 23 whichconnects respectively base portions 24, 26, 28 to contact portions 30,32, 34. In a preferred embodiment extensions 19, 21, 23 extendvertically from an edge of respective base portions 24, 26, 28 of clips18, 20, 22. Preferably, contact portions 30, 32, 34 are spaced from butare oriented parallel to respective bases 24, 26, 28 by respectiveextensions 19, 21, 23.

Contact portions 30, 32, 34 are preferably coplanar with one another anddisposed opposite over a major electrode of the die. A novel feature ofthe present invention making this arrangement possible is extension 19which extends between first major surface and second major surface ofsemiconductor die 10 and connects base portion 24 to contact portion 30,thereby providing a path for electrical connection that extends from aposition over the first major surface of die 10 and its second majorsurface. This configuration allows for the surface mounting ofsemiconductor device 8 on a substrate.

According to another aspect of the present invention, a base portion,e.g. 26, 28 may have a larger area than is necessary for making anelectrical connection to an electrode of semiconductor die 10. Forexample, base 28 of clip 22, which makes an electrical connection tocontrol electrode 16, may be made larger than is necessary for makingthe electrical connection to control electrode 16. A layer of adhesivemay be disposed under this extra area to further strengthen theconnection of clip 22 to the top of semiconductor die 10.

Referring to FIGS. 2A-2B and FIGS. 3A-3C, clips 20, 33, which areconnected to first major electrode 12 and control electrode 16respectively, are unitary bodies formed by bending a sheet of conductivemetal, such as a sheet of copper, to provide a base portion 24, 28 and acontact portion 32, 34 respectively connected and spaced apart byextensions 21, 23 that extends from an edge of base portions 24, 28 toan edge of contact portions 32, 34. Clip 18 used in the first embodimentmay be made according to the same method as described herein for makingthe other clips 20, 22.

A semiconductor device according to the present invention ismanufactured by the following process. Referring to FIG. 4,semiconductor wafer 40, such as a silicon wafer, having a plurality ofindividual semiconductor die 10 formed thereon is first provided.Semiconductor die 10 in wafer 40 are identical and may be MOSFETs,IGBTs, power diodes or the like which are formed on a silicon substrateaccording to any known method. Semiconductor die 10 are separated bystreets 42, which run from one edge of wafer 40 to an opposing edgethereof. Each semiconductor die includes at least a first majorelectrode 12 and a control electrode 16. Second major electrodes 14 forsemiconductor die 10 are disposed on the opposing surface (not shown) ofwafer 8. Electrodes 12, 16 and 14 are preferably solderable.

Referring next to FIG. 5, passivation layer 38 (FIG. 1) having openings44, 46 over respectively first major electrode 12 and control electrode16 is formed. Passivation layer 38 may be formed by depositing a layerof photosensitive epoxy such as a material known as Electra EP2793 overthe entire top surface of wafer 40 covering first major electrodes 12and control electrodes 16 and all areas between these electrodes. Theepoxy may be then dried and exposed to ultraviolet light through a maskto identify and separate the areas that are going to be removed to formopenings 44, 46. The areas so identified are then removed to createopenings 44, 46 which expose portions of first major electrodes 12 andcontrol electrodes 16, respectively. The photosensitive epoxy is thencured by, for example, heating to create passivation layer 38 (FIG. 1)having openings 44, 46.

Openings 44, 46 need only be as large as is necessary to provide a goodelectrical contact between first major electrode 12 and controlelectrode 16 and bases of respective clips, and do not need to expandacross the entire surface of the electrodes. Moreover, openings 44, 46need not expose an area of the electrode equal to the area of bases ofclips connected thereto. In addition, the invention is not limited tothe foregoing process for creating passivation layer 38 (FIG. 1), andany other suitable method may also be used to create passivation layer38 (FIG. 1) having openings 44, 46.

Once openings 44, 46 are formed, conductive attach material 36 (FIG. 1A)is deposited over the exposed portions of first major electrodes 12 andcontrol electrodes 16. Solder or a conductive epoxy may be used asconductive attach material 36 (FIG. 1A).

Referring next to FIG. 6, electrically conductive clips are placed onconductive attach material 36 that is disposed over the exposed portionof each electrode 12, 16. For example, FIG. 6 shows clips 20, 22, whichwere described with reference to semiconductor device 8 according to thefirst embodiment of the invention, connected respectively at theirrespective bases 26, 28 to first major electrodes 12 and controlelectrodes 16 of semiconductor die 10 by conductive attach material 36(FIG. 1A). Once conductive clips (e.g. clips 20, 22) are in place, ifsolder is used as attach material, it is reflown, and if a conductiveepoxy is used as conductive attach material, it is cured. If baseportion of a clip is larger than the exposed area, a layer of adhesivemay be disposed between that portion of the base that is outside theexposed area to further increase the strength of the connection betweenthe clip and the semiconductor die. Optionally, a liquid epoxy may bedeposited over the wafer covering at least parts of base portions of theclips, as well as, other areas of the wafer to improve the strength ofthe assembly of the clips on the semiconductor dies 10. Thereafter,wafer 40 is diced by, for example, sawing, along its streets 42 toproduce individual semiconductor die 10, each having at least oneconductive clip connected to its first major electrode 12 and itscontrol electrode 16.

Another clip, for example, clip 18 as described with respect tosemiconductor device 8 (FIG. 1A) according to the first embodiment ofthe invention, is connected electrically to second major electrode 14 ofsemiconductor die 10 by conductive attach material 36 (FIG. 1A) such assolder or a conductive epoxy. This can be accomplished by picking upeach individual die 10 and placing its second major electrode 14 on baseportion 24 of clip 18 and electrically connecting the same by a layer ofconductive attach material 36 (FIG. 1A) such as solder or conductiveepoxy. Again, if solder is used it is reflown, and if conductive epoxyis used, it is cured.

Alternatively, the die are first singulated by sawing after opening areformed in the passivation layer, and then clips are attached toelectrodes of each die using a conductive attach material.

Clips 18, 20, 22 may be cut from a copper matrix lead frame having aformat similar to copper straps or bridges used in conventionalpackages. Clips 18, 20, 22 may be put into their appropriate place usinga bridge punch and place type operation as found on conventional diebonding machinery. According to a preferred method, die 10 are placed onclips 18 and connected to base portions 24 of the same by an appropriateconductive attach material, conductive attach material is reflown orcured and then clips 18 are trimmed from the strap to obtainsemiconductor devices 8.

A semiconductor device according to the present invention may beproduced by the above-described process to include clips of variousforms. Referring to FIGS. 7 and 8, where like numerals identify likefeatures, semiconductor device 48 according to the second embodiment ofthe present invention includes semiconductor die 10 having clips 50, 52,54 connected to its electrodes. Referring to FIG. 9, where like numeralsidentify like features, clips 50, 52, 54 include a base portion 51, 53,55, respectively. Clip 50 which is connected to second major electrode14 by conductive attach material 36, includes extension 56 whichconnects its base portion 51 to its contact portion 58. Extension 56forms a unitary body with base portion 51 and contact portion 58 of clip50. Also noteworthy is that extension 56 extends between major surfacesof semiconductor die 10.

Base portion 53 of clip 52 has disposed on a surface thereof a pluralityof contacts 60. Base portion 55 also has disposed on a surface thereofcontact 60. Contacts 60 are raised portions which extend from the opensurface of respective base portions 53, 55. Base portions 53, 55 ofclips 52, 54 are electrically connected to first major electrode 12 andcontrol electrode 16 by a layer of conductive attach material 36deposited in respective openings in passivation layer 38. Clip 51 ispreferably formed from copper and plated with silver. Base portion 51 ofclip 50 may have a slightly larger area than the die so that it willform a frame around the edges of the die when the two are attached. Theextra area allows a greater thickness of attach material to be filletaround the edge of the die. Effectively this would allow the attachmaterial to be controlled and stopped from flowing over the edge of thedie.

Indeed, various embodiments of the present invention may be manufacturedby the process described using clips of other forms. For example,referring to FIGS. 10A-10B, 11A-11B and 12A-12B, the clips used may bevaried to include cylindrical contacts 62 as having a flat contactsurface 63 as shown in FIGS. 11A-11B instead of contacts 60 having asemispherical shape as shown in FIGS. 10A-10B and used in the secondembodiment, or contacts 60 may be replaced with a plurality of raisedportions 64 having a flat contact surfaces 65.

The sides of the base portions 53, 55 of clips 52, 54 that are connectedto electrodes of the die may be flat or slightly raised. Raised sidesmay help control the flow of attach material in the same manner as theextra area in base 51 of clip 50. Clips 52, 53 may also be formed fromcopper and finished in silver.

The second embodiment of the present invention is manufactured by firstsingulating the die from the wafer after the passivation layer andopenings therein have been formed. Each singulated die is first attachedto base portion 51 of a clip 50 by a suitable conductive attach materialsuch as a silver loaded epoxy. Clips 52, 53 are then attached using thesame attach material or a suitable solder. Clips 50 act as the base forthe lead frame of a semiconductor device according to the secondembodiment. In the referred manner of manufacturing, clips 50 will bepresent in the form of a high density matrix, while clips 52, 53 will bebonded to the relevant electrodes of the die using a bridge punchassembly.

Referring to FIG. 13, semiconductor device 8 is shown to be surfacemounted on substrate 66. Specifically, contacts 30, 32, 34 are inelectrical contact with conductive pads 68, 70, 72 which connectelectrodes of semiconductor device 8 to their appropriate place withinan electronic circuit (not shown).

Referring to FIG. 14, semiconductor device 48 according to the secondembodiment is shown to be surface mounted on substrate 66. Similar tosemiconductor device 8, semiconductor device 48 is a surface-mounteddevice which is connected to an electronic circuit via conductive pads68, 70, 72, that are in contact respectively with contacts 58, 60 ofclips 50, 52, 54. Due to this arrangement, heat may be dissipated fromsecond major electrode 14 of semiconductor die 10 through base portion24, 51 of clip 18, 50 when a semiconductor device 8, 48 according to thepresent invention is mounted on a substrate.

It is noteworthy that contact portion 30 of semiconductor device 8 (FIG.13) extends in a direction that places it under the same major surfaceof semiconductor die 10 to which the other clips 20, 22 are connected.This configuration has the added advantage of reducing the footprint ofthe semiconductor device. On the other hand, contact portion 58 ofsemiconductor device 48 (FIG. 14) extends in a direction away from thearea under the major surface of semiconductor die 10 to which the otherclips are attached. Although this configuration increases the footprintof the semiconductor device 48, it allows for a larger area forconductive pads 70, 72 under semiconductor die 10. Also, it may besimpler to manufacture as it may not require as precise an alignment ofparts when the second major electrode of the die is to be attached toits respective clip.

The die to footprint ratio in a semiconductive device according to thepresent invention is 90%. The thermal dissipation of a device accordingto the present invention is also improved which allows the device to berun at much higher temperatures. A die used in a device according to thepresent invention may be thinned to 0.100 mm, which is far thinner thanthe die used in conventional packages. A device according to the presentinvention can be used with a variety of footprints. Also, a deviceaccording to the present invention allows the stress imparted by thethermal mismatch between the various substrates to be absorbed when thedevice is assembled. Because of these characteristics, a deviceaccording to the present invention can run harder and used under harsherconditions than conventional devices.

It will be apparent to one skilled in the art that clips of differentforms may be used in combination to devise a semiconductor deviceaccording to the present invention; and, therefore, the devices shownherein should not be understood to limit the scope of the presentinvention. Therefore, although the present invention has been describedin relation to particular embodiments thereof, many other variations andmodifications and other uses will become apparent to those skilled inthe art. It is preferred, therefore, that the present invention belimited not by the specific disclosure herein, but only by the appendedclaims.

1. A semiconductor device comprising: a semiconductor die having a firstmajor surface and a second major surface opposing said first majorsurface; a control electrode and a first major electrode disposed onsaid first major surface of said semiconductor die and a second majorelectrode disposed on said second major surface of said semiconductordie; a plurality of conductive clips each having a base portionelectrically connected to one of said electrodes and a contact portionfor making electrical contact with an external element; wherein saidsecond major electrode is connected to a clip having an extensionconnecting said base portion and said contact portion thereof, saidextension being spaced from said die by an air gap and extending atleast between said second major surface of said semiconductor die andsaid first major surface of said semiconductor die; and wherein saidclip has a free open exterior surface to allow for better heatdissipation.
 2. The semiconductor device of claim 1, wherein saidplurality of conductive clips each includes an extension which spacessaid contact portion from said base portion.
 3. The semiconductor deviceof claim 2, wherein said extension of each conductive clip issubstantially vertically oriented relative to said base portion of eachconductive clip and said contact portion of each conductive clip issubstantially parallel to said base portion of each conductive clip. 4.The semiconductor device of claim 1, wherein said semiconductor die is aMOSFET.
 5. The semiconductor device of claim 1, wherein a passivationlayer is disposed over said control electrode and said first majorelectrode and said base portions of respective conductive clips areelectrically connected to said control electrode and said first majorelectrode through a respective opening in said passivation layer.
 6. Asemiconductor device comprising: a semiconductor die having a firstmajor surface and a second major surface opposing said first majorsurface; a control electrode and a first major electrode disposed onsaid first major surface of said semiconductor die and a second majorelectrode disposed on said second major surface of said semiconductordie; a plurality of conductive clips each having a base portionelectrically connected to one of said electrodes and a contact portionfor making electrical contact with an external element; wherein saidsecond major electrode is connected to a clip having an extensionconnecting said base portion and said contact portion thereof, saidextension extending at least between said second major surface of saidsemiconductor die and said first major surface of said semiconductor dieand wherein a layer of adhesive is disposed between said base portion ofat least one of said clips and said semiconductor die to improve thestrength of the connection between said clip and said semiconductor die.7. The semiconductor device of claim 1, wherein a layer of conductiveattach material connects said base portion of each conductive clip to arespective electrode.
 8. The semiconductor device of claim 7, whereinsaid layer of conductive attach material comprises solder.
 9. Thesemiconductor device of claim 7, wherein said layer of conductive attachmaterial comprises a conductive epoxy.
 10. The semiconductor device ofclaim 1, wherein said plurality of conductive clips include an extensionconnecting their respective base portions to their respective contactportions, each extension forming a unitary body with a respective baseportion and a respective contact portion.
 11. The semiconductor deviceof claim 1, wherein at least one of said plurality of conductive clipscomprises a base portion and at least one contact portion dispose on asurface of said flat base portion.
 12. The semiconductor device of claim11, wherein said at least one contact portion is a bump.
 13. Thesemiconductor device of claim 11, wherein said at least one contactportion is cylindrical and has a flat contact surface.
 14. Thesemiconductor device of claim 11, wherein said at least one contactportion is a raised portion having a flat contact surface.
 15. Asemiconductor device comprising: a semiconductor die having a firstmajor surface and a second major surface opposing said first majorsurface; a first electrode disposed on said first major surface of saidsemiconductor die and a second electrode disposed on said second majorsurface of said semiconductor die; at least one conductive clip having abase portion electrically connected to one of said electrodes and acontact portion for making electrical contact with an external element,said at least one clip having an extension connecting said base portionand said contact portion thereof, said extension extending at leastbetween said second major surface of said semiconductor die and saidfirst major surface of said semiconductor die; and at least anotherconductive clip having a base portion connected to an electrode disposedon a major surface of said semiconductor die opposing to said electrodethat is electrically connected to said at least one conductive clip,said at least another conductive clip including a contact portion formaking electrical contact with an external element, wherein said contactportion extends out of said base portion, and wherein said contactportion occupies less area than an entire external surface area of saidbase portion, whereby when said device is installed on a surface coolingair may circulate and pass by said base portion to cool said die. 16.The semiconductor device of claim 15, wherein said semiconductor die isa MOSFET.
 17. The semiconductor device of claim 15, wherein apassivation layer is disposed over at least one electrode, saidpassivation layer surrounding a conductive layer electrically connectinga base portion of one of said conductive clips to a respective one ofsaid electrodes.
 18. A semiconductor device comprising: a semiconductordie having a first major surface and a second major surface opposingsaid first major surface; a first electrode disposed on said first majorsurface of said semiconductor die and a second electrode disposed onsaid second major surface of said semiconductor die; at least oneconductive clip having a base portion electrically connected to one ofsaid electrodes and a contact portion for making electrical contact withan external element, said at least one clip having an extensionconnecting said base portion and said contact portion thereof, saidextension extending at least between said second major surface of saidsemiconductor die and said first major surface of said semiconductordie; and at least another conductive clip having a base portionconnected to an electrode disposed on a major surface of saidsemiconductor die opposing to said electrode that is electricallyconnected to said at least one conductive clip, said at least anotherconductive clip including a contact portion for making electricalcontact with an external element and wherein a layer of adhesive isdisposed between said base portion and said respective electrode toimprove the strength of the connection between said conductive clip andsaid semiconductor die.
 19. The semiconductor device of claim 17,wherein said conductive layer comprises solder.
 20. The semiconductordevice of claim 17, wherein said conductive layer comprises a conductiveepoxy.
 21. The semiconductor device of claim 19, wherein said at leastanother conductive clip includes an extension connecting its baseportion to its contact portion, said extension forming a unitary bodywith said base portion and said contact portion.
 22. The semiconductordevice of claim 19, wherein said at least another conductive clipcomprises a flat base portion and at least one contact portion disposeon a surface of said flat base portion.
 23. The semiconductor device ofclaim 22, wherein said at least one contact portion is a bump.
 24. Thesemiconductor device of claim 22, wherein said at least one contactportion is cylindrical and has a flat contact surface.
 25. Thesemiconductor device of claim 22, wherein said at least one contactportion is a raised portion having a flat contact surface.
 26. Thesemiconductor device of claim 15, wherein contact portions of saidconductive clips are disposed under one of said major surfaces.
 27. Asemiconductor device comprising: a semiconductor die having a firstmajor surface and a second major surface opposing said first majorsurface; a first electrode disposed on said first major surface of saidsemiconductor die and a second electrode disposed on said second majorsurface of said semiconductor die; at least one conductive clip having abase portion electrically connected to one of said electrodes and acontact portion for making electrical contact with an external element,said at least one clip having an extension connecting said base portionand said contact portion thereof, said extension extending at leastbetween said second major surface of said semiconductor die and saidfirst major surface of said semiconductor die; and at least anotherconductive clip having a base portion connected to an electrode disposedon a major surface of said semiconductor die opposing to said electrodethat is electrically connected to said at least one conductive clip,said at least another conductive clip including a contact portion formaking electrical contact with an external element and wherein saidcontact portion of said at least one conductive clip is disposed undersaid major surface to which said at least another clip is connected. 28.The semiconductor device of claim 15, wherein said base portion of saidat least one conductive clip extends away from an area under a majorsurface to which said at least another clip is connected.